Means for use in association with range-finders.



A. BARR L w. soun. MEANS FOR USE IN ASSOCIATION WITH RANGE FINDER'S.

APPLICATION FILED NOV. II, 1913. v 1,164,326. f .Patented Dec. 14, 1915.

Y F/a:/.

A. BARR 6L W, STROUD MEANS FOR USE; IN ASSOCIATION WITH RANGE FINDERS.

APPLICATION FILED Npv.|1, |913.

1,164,326. v Patented Dec.14, 1915.

, with, Range-Finders,

.Uni-TED ,STATES PATENT/"onirica r ARCHIBALD :Bann AND WILLIAM s'rRoUD, or ANNIESLAND, omiseovv,v SCOTLAND) MEANS non U'sE 1N ASSOCIATION wrm minos mananaA Be it known that We, ARCHIBALD, BARR and WILLIAM STROUD, subjects of the King of Great Britain and Ireland, and both of Caxton, street, Anniesland, Glasgow, Scotland, have invented new and useful Improvements in Means'for Use in Association (for which We have made application forpatent in Great Brit-- ain, No. 26.333, bearing date November 16, 1912,) of which Ythe following is a specilication.

This invention relates to the provision of apparatus for use iny conjunction with a rangefinder having a normal base and alternatively a` reduced base which may be associated in construction with the rangevfinder for which it is to be used, or provided as a separate apparatus, the apparatus comprising two reciprocal scales of ranges, each capable of adjustment relative to an index, and a subsidiary scale and subsidiary index, the adjustment of one of the reciprocal .scales of ranges being adaptedto be made in accordance 1with ranges tindicated when the rangefindcrwas'used on an object with the reduced-'base and the adjustment of the other yreciprocal scale of ranges being adapted tol made in accordance with ranges indicated when the rangefinder was used on the same object with the normal base, the adjustment of the two scales of ranges ail'ecting the relative adjustment of the subsidiary scale and subsidiary index, and thereby indicating `Whether the readings correspond, or the extent to Which they differ in terms of measurement corresponding to the extent type. the

"tical axes of the double telescopic system sol as to reduce the base length, in order A(for the purpose of testing the instrumenaas to adjustment), to enable observations to be Specification of Letterslfatent.

order to adjust the of the self-contained `No. 944649 of 1909. -reieetors in their normal position for rangefinding lwhen using the normal or long base Patented Dec. 14e, '1915.

Application led November 1'1, 1913. Serial 800,341.

'taken on a distant object using the normal base length, and the readings from these observations are the readings Which are compared by the use' of apparatus constructed according to this invention. If the range of a target is changing uniformly three observatlons may be taken, for example, (l)

. with the long base, (2) with the short base,

and (3) with the long base again,l and the mean ofv the two ranges taken with the long base may be compared with the range observed when using the short base.

A rangeiinder and some examples of apparatusadapted for use in conjunction therewith in accordance with this invention will non ybe described with reference to the accompanying drawing, in which:w-

Figure 1 is a diagrammatic plan partly in section of a rangeiinder suitable for use in conjunction with means according to this invention. Figs. 2 and 3 are elevations of an appliance,l and Fig. fr isan elevation of a modified-appliance, adapted to be associated -in construction with a rangeiinder or in the construction 'of a separate apparatus according to this invention. Figs. 5, 5a show in sectional elevation, Figs. G, 6 show in sectional plan, andv Fig. 7 is an end view oi' one end of a rangefinder suitable for use in conjunction with' means according to this invention. A

In' Fig.' l there jis represented a rangevnder having an opter tubel in which is suitably supported ga doubletelescopic system 2 adapted for coincidence (erect or in vert), sterescopi or other measurementl of angles, vwith objectives 3 and 4, looking, the

former to the left and the latter to 'the right. It is unnecessary toshoW such optical details as eyepiece prisms and eyepiece,

` kor-eyepieces, between the objectives, as these with which may be of a very large variety of types, such, for example, as that described by Barrand Stroud, the present applicants, in -Patent 5 and Gare two endof the instrument. These'end-refiectors 5 and 6 are shown as pentagonal doubly refleeting prisms, but they may be constructed after the fashion of any other type of optical adjustment the. end-reflectors 5 and 6 may be transferred by square. For purposes of any suitable-mechanism to the positions 7 and 8 respectively vmen a new observation of the range may be obtained 'using the the rangender when in adjustment ought to indicate n times the range with the short hase that it does With the long hase. In order to adapt the method of reading` the required correction for this case, all that is necessary is to replace the scale upon the ring 10 (Figs. 2 and l) or the ring; 1G (Figt t) by a scale having the length romthe infinity mark to any given range indication n times the length between the corresponding marks onl the scale or ring 9 (or the ring 15). Thus, for example, it' the short hase reading is one-third of the normal base length reading ot' the rangelinder, the scale on 1() (or 1G) will hare three times the lengt-h -treatin-{init}1 to 1000 meters that the corresponding interral on the scale 9 (or 15) has. In other words 10 (or 16) will have the same length from the infinity mark to 5000 meters as the scale on (or 15) has for its inlinitjvI mark to the indication 1.000 meters.

The rings and 'l0 (or l5, 16 and '21) need not be on the rangeinder itself, but might, for example, he upon the mounting, or associ ated in the construction ot a. separate apparatus, and obviously other arrange ments of scale (such, for eaniple, as scales on disks or stripsl may he used instead ott scales upon rings. v.

It will he recognized that with a rangefinder ot' the.ex aun)le illustrated instead of 'provision being iliade for moving hoth the prisms 5 and G, one only need he so mounted to produce an alteration of the lenfthcf thc optical hase ofthe rangefinder.

Ne claimz 1. Apparatus for use in conjunction with rangelinder haring a normal base and al-v inatively reducedrhasc comprising two reciprocal scales of rangD s, each capable of Iadjustment relative to an index, and a sub- A-a-sidiary scalo and subsidiary index, the adjustment o'l" one o? the scales of ranges being adapted to he made in a cordance With readings cf ranges .indicat d vwhen the rc finder was used on an .ihiect with the i duced base and the adinstinent of the other scale of ranges 'ticino' adapted to he made in. accordance wits reading; of ranges indicated when the ra'tngeiinder was used on the same object with the normal hase, the adiustments oi' the two scales ott ranges affecting the rel-Y ative adjustment of the subsidiary scale and subsidiary index, for the purposes set forth.

2. Apparatus for use in conjunction with a rangelinder having a normal base and alternatively a reduced hase, comprising` two reciprocalscales of ranges, two indexes, one for each scale', the scales'oi? ranges being cach capable of adjustment to its respective one o'l the scales in accordance lwith the readings ci ranges indicated when the rangeinder was used with the short and the other `ith the long hase, and a subsidiary scale and subsidiary index for 'indicating the required correction, for the purposes set forth.

."l. Alinparatus for use in conjunction with im'igeiinder haring a normal base and altorinitively a 'reduced base, comprising two reciprocal scales ot' ranges of thesame spac-` injj. two indo: one for each scale`Y the salcs ot ranges being each capable of ad- ,p ,lint to its respective index, 'one of the scales ranges indicated when the rangeiinder Was used with the short hase and the other with the long hase and a subsidiary scale and subsidiary index, tor tl purposes forthr lt. Apparatus tor use i conjunction with a razioetinder caring a zY 'mal hase and al- -rnatively a reduced hase., consisting et two rotatable rings, a reciprocal scaie upon each .of the rings, two inc f, one creach reciprocal scale, subsidiary scale and, index, 'for the purposes set forth.

Apparatus tor conjunction 'with a rangetindei.' having,` a normal hase and al ternatirely a reduced hase, conv olZ two rotatable rings, reciproca selle or-on each ofi the rings, trio inde-5ms, one r o n reciprocal scale, a' tl` ro ile rl subsidiarT 'on 'tl ting, a he ARCHBALD Bilil'lt. i 'WLLAM S'R'OU. vVVitn-csses:

NE1L T. MACLRA'N, J Aims. lvVnsT Enns cn. 

